OpenStack and other hackish things

This is the next installment in the never-ending series of OpenStack image builds. Today's
target: CentOS

Image Characteristics

The usual suspects are present:

minimal package install

serial console support

timezone is Etc/UTC

hostname set to instance name

a single partition with root filesystem, no swap

grow root filesystem to device size

enable EPEL (install epel-release)

enable could-init repo to get 0.7.1

A few things are still lacking:

selinux is in permissive mode, make enforcing

strengthen default firewall

Build

Tools like Oz are a good idea in theory but in practice seem to be quite picky about the environment
they will correctly run on. I'm looking at you libguestfs. Other tools like the venerable appliance-creator get hung up
on needing the same version of things in the host as in the chroot.

Good ole virt-install happily runs on damn near everything. This build has been tested
on CentOS 6.4 and Ubuntu 12.10. TODO(dtroyer): don't run this all as root